1. Field of the Invention
The present invention generally relates to etched articles and, more particularly, to methods of etching articles.
2. Description of the Related Art
It is known to etch or inscribe a diamond surface by aiming a laser beam directly at the diamond surface, and by moving the laser beam and the diamond surface relative to each other to create a desired etched pattern. See, for example, U.S. Pat. No. 4,392,476 and U.S. patent application Ser. No. 09/785,631, filed Feb. 16, 2001.
It is also known to create ornamental articles of jewelry by directing a laser beam through a light-transmissive cover for impingement on a precious metal substrate, such as a gold foil or disc, and by moving the laser beam and the substrate relative to each other to create a desired etched pattern. See, for example, U.S. Pat. No. 5,609,043 and U.S. Pat. No. 5,799,511.
It is further known from U.S. patent application Ser. No. 09/909,174, filed Jul. 19, 2001, to apply a high melting point material over a diamond surface, and to heat the material to create a desired etched pattern on a gemstone. The pattern can be formed by a stencil, or by moving a source of radiant energy such as a laser relative to the diamond surface.
All these techniques involve the direct etching of articles of considerable worth, i.e., diamonds and gold substrates. Etching errors are costly. Burn holes through the substrates or burn marks in undesired placed on the diamonds or substrates detract from the overall aesthetic appeal.
It is an object of this invention to create an etched article of high quality and of inexpensive manufacture, especially a decorative article suitable for use as jewelry.
In keeping with this object, one feature of this invention resides in a substrate marking system and method that apply a fusible coating of a high melting point material on a lower surface of the substrate, for example, a transparent disc. The coating is applied over the entire surface of the disc. A high melting point substance or mixture having a melting point greater than that of the substrate is used for the coating. The substance or mixture is exposed to an energy source and heated to heat the surface in a marking pattern. The energy source, preferably a laser, emits a laser beam and directs the laser beam and/or the substrate to move relative to each other along the marking pattern. The laser beam passes through the substrate. The coating may be applied in any thickness since the marking is not dependent on the thickness of the coating.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.